title: Transient absorption spectroscopy studies on polythiophene-fullerene bulk heterojunction organic blend films sensitized with a low-bandgap polymer.
abstract: Recently, the concept of near-infrared sensitization is successfully employed to increase the light harvesting in large-bandgap polymer-based solar cells. To gain deeper insights into the operation mechanism of ternary organic solar cells, a comprehensive understanding of charge transfer-charge transport in ternary blends is a necessity. Herein, P3HT:PCPDTBT:PCBM ternary blend films are investigated by transient absorption spectroscopy. Hole transfer from PCPDTBT-positive polarons to P3HT in the P3HT:PCPDTBT:PCBM 0.9:0.1:1 blend film can be visualized. This process evolves within 140 ps and is discussed with respect to the proposed charge-generation mechanisms.
authors.affiliation: i-MEET WW6, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstraße 7, 91058 Erlangen, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Löslein
authors.forename: Tayebeh
authors.initials: T
authors.lastname: Ameri
authors.forename: Gebhard J
authors.initials: GJ
authors.lastname: Matt
authors.forename: Markus
authors.initials: M
authors.lastname: Koppe
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Egelhaaf
authors.forename: Anna
authors.initials: A
authors.lastname: Troeger
authors.forename: Vito
authors.initials: V
authors.lastname: Sgobba
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Brabec
mesh_terms: D055664:Electrochemical Techniques; D037741:Fullerenes / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D012993:Solar Energy; D013057:Spectrum Analysis; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D011108:Polymers; D013876:Thiophenes; C066730:polythiophene
keywords: conjugated polymers; organic electronics; photochemistry; solar cells; thin films